Lingua Volgare Shorthand

[pfeaster]

Understanding what a shorthand is and how it functions is nonetheless a requirement for even being open to such a solution displaying different statistical properties.

I've studied a number of older shorthand systems, and one feature they all seem to share in common is that they methodically replace the letters of the alphabet with simpler, easier-to-form characters as a means of saving time.  For example, the character for [s], as a letter or a phoneme, should be faster and simpler to write than a conventional [s].  The Voynichese characters in your key don't seem to satisfy that criterion -- your Voynichese [s], for example, would take considerably longer to write than a conventional early fifteenth-century [s].

It seems reasonable enough to suggest that the plaintext behind Voynichese might be a highly abbreviated and contracted written form of a vernacular language.  But even if it were, I'd have reservations about calling it "shorthand," except in a casual or colloquial sense -- there's nothing about the design of the characters that points to any interest in attaining higher writing speeds.